An antenna may include a transducer designed to transmit or receive electromagnetic waves. Antennas may convert electromagnetic waves into electrical currents and electrical currents into electromagnetic waves. An antenna may have a physical structure including an arrangement of conductors that generate a radiating electromagnetic field in response to an applied alternating voltage and the associated alternating electric current. Additionally, an antenna may be placed in an electromagnetic field so that the field will induce an alternating current in the antenna and a voltage between its terminals. Antennas often may utilize radiating elements capable of transmitting and/or receiving electromagnetic energy.
Metamaterials may include materials designed to have magnetic or electric resonances. Generally, a metamaterial may have structural features smaller than the wavelength of the electromagnetic radiation with which it interacts. Additionally, metamaterials may include artificial materials constructed into arrays of current-conducting elements with suitable inductive and capacitive characteristics. Further, a metamaterial may have a negative refractive index.
When an electromagnetic wave interacts with a metamaterial, the metamaterial interacts with the electric and magnetic fields of the electromagnetic wave. These interactions may include altering the electromagnetic wave, such as bending or absorbing light.